With the development of liquid crystal display technologies, higher requirements are put forward for the quality of a picture displayed by a liquid crystal display device. Improvement in the brightness of the liquid crystal display device enables more natural and beautiful pictures displayed, and thus is an important content in enhancing picture quality. The main measures for high brightness design include increasing the brightness of a backlight and improving the transmittance of a display screen. Increasing an aperture ratio of a pixel unit can effectively improve the transmittance of the display screen.
The aperture ratio of a pixel unit refers to a ratio of an effective light transmission area in the pixel unit of the liquid crystal display device to an entire area of the pixel unit. Because signal wires for driving switch elements are provided between pixel electrodes of different pixel units on an array substrate, and gaps formed between the signal wires and the pixel electrodes will cause light leakage, it is necessary to provide a black matrix on a CF substrate for light shielding. However, the black matrix will seriously affect the aperture ratio of the pixel unit.
At present, improvements that have been made to the black matrix include the BM on array technology in which the black matrix is arranged on the array substrate, and thinning of data line wiring. Among them, the black matrix can be arranged on the array substrate to reduce a size designed for the black matrix while the requirements for cell alignment are satisfied. However, such a technology is not widely spread due to material limitations. And thinning of wiring will lead to insufficient data write capacity and in-plane DC deterioration, and thus lead to deterioration of brightness uniformity, screen flickering, long-term residual images and other adverse effects. Therefore, there is no effective solution to the problem of decreased aperture ratio of the pixel unit caused by the black matrix.
To conclude the above, it is urgent to improve the black matrix, so as to improve the aperture ratio of the pixel unit.